We Do Not See The Same Landscape Perspectives and Development of A Common Spatial Framework By Robert A. Washington-Allen Research and Development Staff Scientist DOE Oak Ridge National Laboratory Oak Ridge, TN

A Spatial Framework is a mapped set of geographic regions that supports agency programs or studies McMahon et al. (2001) Environ. Manage. 28:

T4,T6 T4 Shrubland Native Grassland T3 T3,T5 Introduced Grasses> 60 % Shrub Dense Shrubland T1: fire, T2: grazing, T3: heavy grazing, T4: cultural inputs, T5: drought, T6: wetter than average years Threshold T5 T2 T1,T6 shrub grass/bare soil sparse grass/ bare soil dense grass/ bare soil denser grass/ bare soil Landscape Composition and Configuration

Each region is relatively homogenous and distinct from adjoining regions. Distinctions are of two types: Specific characteristics of interest Broader categories of resource potential

Specific characteristics of interest

Political

Regional GAP Analysis

NRCS STATSGO

Broader categories of resource potential Quantitative vs Weight-of-Evidence (Qualitative) Methods Visual Pattern Recognition vs Data-Driven Perspectives

Bailey (1995, 1996) delineated 52 ecoregions at the finest province level, increased from 30 in his original Bailey (1983) version. Other, different ecoregions, based on other criteria and for other purposes, have been specified by Holdridge (1947), Walter and Box, Thornwaite, Koppen and many others. Because the delineation is based on subjective criteria, there are as many sets of ecoregions as there are experts.

US EPA : Omernick's 1987 aquatic ecoregions were based on perceived patterns of a combination of causal and integrative factors, including land use, land surface form, potential natural vegetation, and soils. Although delineated for national- level studies of water resources, Omernick's 76 national ecoregions have been borrowed for many other kinds of ecological studies as well.

The National Resources Conservation Service (NRCS) has developed a version of ecoregions called Major Land Resource Areas (MLRAs). MLRAs are much finer than most of the other types of ecoregions; for example, there are 78 MLRAs in the 13 southeastern states. MLRA boundaries are drawn with regard to edaphic and physiographic relationships, but are still subjective.

Major Land Resource Areas (MLRA)

Clustering is data-driven and empirical. This objectivity means that one obtains the same result every time, given the same data and a request for the same number of clusters. This is in contrast to regions drawn by expert opinion.

U.S. Forest Service Southern Global Change Program National map clustered on elevation, edaphic, and climate variables into 3000 ecoregions using similarity colors.

Towards a Common Spatial Framework Regions are areas within which abiotic and biotic capacities and potentials are similar. Foster an ecological understanding of a landscapes terrestrial and aquatic resources. Provide the basis for interagency coordination and collaboration in the design and implementation of ecosystem research, assessment, and management. Fully integrated Peer-reviewed (participating agencies) National Map developed with common objectives.